1. Field of the Invention
The invention relates to a method for producing a package for an electronic circuit with a substrate. The invention also relates to a substrate for a package for an electronic circuit.
2. Description of the Related Art
Integrated circuits are usually fitted in packages. To make terminal areas of the integrated circuits accessible via terminal contacts of the package, packages usually have wiring devices which provide an electrical connection between the terminal contacts and the terminal areas. For this purpose, some types of package have wiring interposer circuit boards, which are formed with one or more layers and on the upper side of which the integrated circuit is arranged and connected to interconnects located on it and on the underside of which the terminal contacts are provided. The connection between the integrated circuit and the terminal contacts takes place by way of conduction regions and/or plated-through connections through the circuit board.
During a signal transmission, signal crosstalk and interferences may occur on the signal lines and supply lines through the circuit board especially when transmitting high-frequency signals. These effects are usually reduced by providing suitable passive components, such as resistors and capacitances, which are provided on a system board and are electrically connected to the terminal contacts. The provision of resistors and capacitances that are separate from the integrated circuit requires additional space on the system board. Moreover, the provision of additional components significantly increases the probability of defects occurring in a system as a whole.
Multilayer printed circuit boards for packages for electronic circuits are used wherever the integrated circuit has to be in connection with so many terminal contacts that crossing lines between the terminal contacts and the terminal areas of the electronic circuit cannot be avoided. The multilayer printed circuit boards are produced by introducing corresponding interconnects between layers of the circuit boards before the layers are bonded to one another. This represents a complex process, making the packages for such electronic circuits very expensive.